NAME

j_flow.d - snoop Java execution showing method flow using DTrace.

SYNOPSIS

j_flow.d

DESCRIPTION

This traces activity from all Java processes on the system with hotspot provider support (1.6.0) and the flag "+ExtendedDTraceProbes". eg, java -XX:+ExtendedDTraceProbes classfile

This watches Java method entries and returns, and indents child method calls.

OS

Solaris

STABILITY

Evolving - uses the DTrace hotspot provider, which may change as additional features are introduced. Check Java/Readme to see what version these scripts are based on.

EXAMPLES

Default output,: # j_flow.d

FIELDS

C: CPU-id
TIME(us): Time since boot, us
PID: Process ID
CLASS.METHOD: Java class and method name

LEGEND

->: method entry
<-: method return

WARNING

Watch the first column carefully, it prints the CPU-id. If it changes, then it is very likely that the output has been shuffled. Changes in TID will appear to shuffle output, as we change from one thread depth to the next. See Docs/Notes/ALLjavaflow.txt for additional notes.

DOCUMENTATION

See the DTraceToolkit for further documentation under the Examples, Notes and Docs directories. The example files may be especially useful as they aim to demonstrate how to interpret the output.

EXIT

j_flow.d will run until Ctrl-C is hit.

AUTHOR

Brendan Gregg [CA, USA]